Experimental and theoretical investigation for inhibition action and adsorption behavior of montelukast sodium in 1 M HCl solution

Abstract

Inhibition behavior of Montelukast sodium (2-[1-[[1-[3-[2-[(7-Chloro-2-quinolyl)] vinyl] phenyl]-3-[2-(1-hydroxy-1-methyl-ethyl)phenyl]-propyl]sulfanylmethyl]cyclopropyl]acetic acid sodium salt) for corrosion of mild steel (MS) in 1 M HCl solution was studied by weight loss, electrochemical and quantum chemical methods. Montelukast sodium showed good inhibition efficiency (97% observed at 100 ppm). Polarization study indicated mixed-type nature of the inhibitor. The adsorption of the inhibitor followed Langmuir adsorption isotherm. Quantum chemical calculations provided good support for the adsorption of inhibitor molecules on the mild steel surface. Mechanism of inhibition was further corroborated by the values of activation parameters obtained from the experimental data. Optical microscopy was used to characterize the metal surface before and after adsorption of inhibitor. © 2012 by ESG.